Suprachiasmatic nucleus: use of 14C-labeled deoxyglucose uptake as a functional marker.

Glucose consumption of the rat suprachiasmatic nuclei (SCN) was studied under various experimental conditions by means of the [14C]deoxyglucose (DG) technique. The results show that glucose consumption of the SCN, in contrast to other brain structures, is a function of both the time of day and environmental lighting conditions. These data are consistent with the hypothesis that the SCN have an essential role in circadian rhythm regulation and indicate that the DG technique may provide a novel approach for the study of the central neural mechanisms underlying circadian rhythm regulation.